Polycystic Ovary Syndrome (PCOS)

Definition | Aetiology | Pathophysiology | Risk Factors | Clinical Presentation | Investigations | Management | When to Refer | References

Definition

Polycystic Ovary Syndrome (PCOS) is a common endocrine disorder affecting women of reproductive age. It is characterised by a combination of symptoms related to hyperandrogenism, ovulatory dysfunction, and polycystic ovaries on ultrasound. PCOS is a leading cause of infertility and can have significant long-term health implications.

Aetiology

The exact cause of PCOS is not fully understood, but it is believed to result from a combination of genetic and environmental factors. Insulin resistance and hyperinsulinaemia are key contributors to the condition, promoting excess androgen production by the ovaries.

Pathophysiology

PCOS involves a complex interplay of hormonal imbalances:

• Hyperandrogenism: Elevated levels of androgens (male hormones) lead to symptoms like hirsutism, acne, and alopecia.
• Insulin Resistance: Many women with PCOS have insulin resistance, leading to compensatory hyperinsulinaemia. This exacerbates ovarian androgen production and contributes to anovulation.
• Ovarian Dysfunction: The ovaries produce multiple small follicles that do not mature, leading to irregular or absent ovulation and the formation of multiple ovarian cysts.

Risk Factors

Several factors increase the likelihood of developing PCOS:

• Family History: A family history of PCOS or type 2 diabetes increases the risk.
• Obesity: Excess weight is strongly associated with the development and worsening of PCOS symptoms.
• Insulin Resistance: Women with insulin resistance or a family history of insulin resistance-related conditions are at higher risk.
• Ethnicity: PCOS prevalence may vary by ethnicity, with higher rates observed in South Asian women.

Clinical Presentation

PCOS presents with a range of symptoms, which can vary in severity. Common symptoms include:

• Menstrual Irregularities: Infrequent, irregular, or prolonged menstrual cycles. Some women may experience amenorrhoea (absence of periods).
• Hirsutism: Excess hair growth on the face, chest, and back due to elevated androgen levels.
• Acne: Persistent, severe acne that does not respond well to standard treatments.
• Scalp Hair Thinning: Androgenic alopecia, characterised by thinning hair on the scalp.
• Weight Gain: Difficulty maintaining a healthy weight, with weight often concentrated around the abdomen.
• Infertility: Difficulty conceiving due to irregular ovulation or anovulation.
• Acanthosis Nigricans: Dark, velvety patches of skin, particularly in skin folds, associated with insulin resistance.
• Mood Disorders: Increased risk of depression and anxiety.

Investigations

Diagnosing PCOS involves a combination of clinical assessment, blood tests, and imaging:

• Clinical Assessment: A detailed history and physical examination focusing on menstrual irregularities, signs of hyperandrogenism, and weight management.
• Blood Tests:
  • Androgen Levels: Elevated total testosterone and free androgen index support the diagnosis.
  • Luteinising Hormone (LH) and Follicle-Stimulating Hormone (FSH): An elevated LH to FSH ratio may be observed, although it is not diagnostic.
  • Fasting Glucose and Insulin Levels: To assess for insulin resistance.
  • Lipid Profile: To evaluate cardiovascular risk.
  • Thyroid Function Tests and Prolactin Levels: To rule out other causes of menstrual irregularities.
• Pelvic Ultrasound: Used to identify polycystic ovaries, defined as the presence of 12 or more small follicles (2-9 mm) in each ovary or increased ovarian volume. This is part of the Rotterdam criteria for diagnosing PCOS.

Management

PCOS management focuses on symptom control, improving fertility, and reducing long-term health risks:

Lifestyle Management

• Weight Management: Weight loss through diet and exercise can improve symptoms and restore ovulation in overweight women.
• Dietary Changes: A balanced diet with a low glycaemic index (GI) can help manage insulin resistance and weight.
• Exercise: Regular physical activity helps improve insulin sensitivity, reduce weight, and alleviate symptoms.

Medical Management

• Menstrual Regulation:
  • Combined Oral Contraceptive Pill (COCP): Helps regulate menstrual cycles, reduce androgen levels, and manage hirsutism and acne.
  • Progesterone-Only Therapy: Such as medroxyprogesterone acetate (Provera) to induce withdrawal bleeds and prevent endometrial hyperplasia in women who do not tolerate COCP.
• Fertility Treatment:
  • Clomifene Citrate: First-line treatment for inducing ovulation in women with PCOS who wish to conceive.
  • Metformin: Used to improve insulin sensitivity and may help restore ovulation, particularly in women who are overweight or have insulin resistance.
• Androgen Reduction:
  • Anti-Androgens: Such as spironolactone, used to treat hirsutism and acne, often in combination with COCP.
• Insulin Sensitisation:
  • Metformin: Used to manage insulin resistance, particularly in women with impaired glucose tolerance or type 2 diabetes.

Psychological Support

Due to the impact of PCOS on mental health, addressing psychological wellbeing is crucial. Referral for counselling or support groups may be beneficial for those struggling with body image, mood disorders, or infertility-related stress.

When to Refer

Referral to a specialist (e.g., endocrinologist, gynaecologist, or fertility specialist) is warranted in the following situations:

• Failure to conceive after 12 months of trying with appropriate ovulation induction therapy.
• Severe symptoms of hyperandrogenism not responding to first-line treatments.
• Significant psychological distress related to PCOS that requires specialist intervention.
• Complex cases requiring specialised hormonal or metabolic management.

References

1. NHS (2024) Polycystic Ovary Syndrome (PCOS). Available at: https://www.nhs.uk/conditions/polycystic-ovary-syndrome-pcos/ (Accessed: 26 August 2024).
2. National Institute for Health and Care Excellence (2024) Polycystic Ovary Syndrome: Diagnosis and Management. Available at: https://www.nice.org.uk/guidance/ng209 (Accessed: 26 August 2024).
3. British Medical Journal (2024) Polycystic Ovary Syndrome: Diagnosis and Management in Primary Care. Available at: https://www.bmj.com/content/350/bmj.h2448 (Accessed: 26 August 2024).

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